The modern automotive internal combustion engine has been recognized as a principal contributor to atmospheric pollution, and a number of different approaches have been made to the problem. Devices of various sorts have been developed to control release of crankcase emissions and others have been developed to remove harmful products from the exhaust gases. It has, however, been recognized that the basic problem would be much ameliorated if the engines could be operated under substantially ideal conditions so that only small amounts of the objectionable pollutants would be produced, as by insuring substantially complete combustion of the engine fuel under all operating conditions. Examples of devices for such purpose are illustrated and described in Mokrzycki U.S. Pat. No. 3,039,449 and Canadian Pat. No. 590,030, as well as in Thomasson U.S. Pat. No. 1,259,317. While illustrating this general approach to the problem, such devices have not been flexible enough in operation quickly to accommodate rapid changes in engine operating conditions, such as rapid acceleration and rapid deceleration, to insure a proper air/fuel ratio at all times and thereby achieve substantially complete combustion of the fuel.
Substantially improved results have been obtained with the valves and air supply systems of the aforementioned MacGuire U.S. Pat. Nos. 3,693,650 and 3,799,132 which supply primary air to the engine manifold of an internal combustion engine over substantially the entire speed range of the engine for improved engine response and acceleration. Such valves and systems insure automatic adjustment to various throttle settings and rates of acceleration or deceleration, which in the past have commonly resulted in a temporary improper fuel/air mixture, and prevent the emission of excessive pollutants to the atmosphere, particularly carbon monoxide and hydrocarbon vapors.
It has been found, however, that improved performance of such valve and air supply systems can be obtained by proper adjustment of the valves to cause the valves to resonate over the full operating range of the engine, that is, during idle as well as during cruising and acceleration and deceleration. As the valves resonate, air pulsations are created causing turbulence in the air flow through the valves and into the carburetor where pressure waves are set up in the lower part of the carburetor and manifold which assist in breaking up the fuel into smaller, more uniform particle sizes in addition to maintaining a more constant air/fuel mixture over the full operating range, for improved combustion efficiency, fuel economy, and lower exhaust emissions.
It has also been found that making the valve housings with a right angle turn in the outlet or in the shape of a Tee and plugging one of the arms of the Tee has a beneficial effect in causing the valve to resonate. Also, utilizing a hard plastic such as hard nylon or metal tubing for the delivery line from the valves to the carburetor causes the delivery line to resonate and thus assist in maintaining the air pulsations during passage through the delivery line just prior to entering the carburetor. The pulsating air from the valves may also effectively be mixed with the air from the positive crankcase ventilation line prior to entering the carburetor to impart pulsations to the air passing through the PCV line as well to maximize the amount of pulsating air flowing into the carburetor.
The plastic balls for the valves are desirably pressure molded for more uniform and consistent results, and are preferably made of a suitable thermosetting material rather than a thermoplastic so as to withstand greater temperature variations without adversely affecting the capabilities of the balls to resonate. Using an O-ring or a suitable non-hardening sealer around the threads of the valve casings or both to prevent air from entering the valves except through the normal valve inlets also provides for better resonance.
With the foregoing in mind, it is a principal object of this invention to provide a valve and supplemental air supply system to the manifold of an internal combustion engine which produces air pulsations causing turbulence in the air flow through the valve and into the carburetor to assist in obtaining smaller, more uniform fuel particle sizes and maintaining a more constant air/fuel mixture over the full operating range of the internal combustion engine.
Another object is to provide a method by which such valve and system may be adjusted for maximizing such air pulsations.
Still another object is to provide such a valve and system in parallel with the positive crankcase ventilation line so that the pulsating air from the valve also imparts pulsations to the air passing through the PCV line to maximize the turbulence of the air flow entering the carburetor.
Another object is to provide such a valve and system which will obtain more uniform and consistent results over a greater temperature range resulting in greater combustion efficiency and fuel economy, and reduced exhaust emissions.